Electric plug lifter



Oct. 25, 1938. J.-J.SHEERAN 2,134,345

ELECTRIC PLUG LIFTER Filed Aug. 18, 1956 5 m mmmmn m 4 Patented Oct. 25, 1938 UNITED STATES PATENT OFFICE dclaims.

My invention relates to attachment plugs and more particularly to means to facilitate removal of attachment plugsand the like from their associated receptacles or sockets.

s It frequently happens, in the use of conventional attachment plugs, that the operator removes the top or cap portion from the plug base or from a wall receptacle by pulling on the electrical card. This is not only injurious to the 10 cord, but it also tends to loosen the terminals.

If the pull is not in a direction normal to the receptacle, the contacts are liable to become bent and if the connection is with a heating unit, for

example an electric iron or other-high resistance 16 piece, there may be considerable arcing which creates a fire hazard. Various means have been adapted to prevent loosening of the cord termi nals and to prevent strain on the portion of the cord interiorly of the plug cap and the screw I terminals to which the conductors are attached. A conventional method comprises forming a knot at the end of the cord which is adapted to seat in the recessed portion of the cap and sometimes I a strain insulator is attached directly to the cord within the cap. While these devices overcome the tendencyof breaking or separating the cord from the terminals, they will not prevent injury to the contact blades when the operator withdraws the attachment plug cap by pulling on the cord, in a direction at an angle to the plane of contact surface of the plug or receptacle.

Heretofore, it has been proposed to provide means for releasing attachment plugs from their sockets or receptacle by using devices designed 35 to exert a pressure between the cap and its socket or receptacle. In accordance with one arrangement, the cap is provided with a bell crank device built into the body of the attachment plug cap; it has also been suggested to use a piston 40 or plunger adapted to slide longitudinally of the plug body, and the caps have been formed with handle members exteriorly thereof, adapted to be grasped by the operator, for the purpose of withdrawing them from a receptacle. While the prior art devices will no doubt operate to release a cap from its plug or receptacle, they are open to several objections. As far as I am aware, they.

have all heretofore been built into the plug, that is, formed integrally with the cap member. If 50 the attachment plug becomes damaged, it is necessary not only to discard the plug but also the lifting device associated therewith. In those devices in which a bell crank arrangement is used, the forces exerted between the receptacle and 1 the cap are not uniformly distributed, a quick break is not alwaysobtained when it is attempted to release the plug and further there is a possibility of short circuiting the blade contact members of the plug.

It is thepurpose of the present invention, to I overcome the diificulties encountered in the prior art devices enumerated above, and to provide a lifting device, in the form of an attachment adapted to be quickly and easily mounted exteriorly of a plug cap, radio tube base, or the like.

v The device is of general application inconnection with various types of separable electrical con-' nectors. It consists of but few parts, is strong and sturdy in construction and not liable to get out of order even after long and continued use. f

An object of my invention is to provide an attachment for disconnectable parts of electrical connectors, wherein the separable or removable portion of the connector may be quickly and easily disconnected from its cooperative receptacle or socket. Another object, of my invention is to provide a detachable lifting device for attachment plugs, whereby a plug may be easily released and disconnected from its associated socket or re- 85 ceptacle.

Yet another object of my invention is to provide an attachment for disconnect'able parts of electrical connectors, wherein the separable or removable portion of the connector may be forced 80 outwardly away from the normal operative position in -its associated socket or receptacle.

Still another object of my invention is to provide an-attachment for disconnectable parts of electrical connectors, for example attachment plugs and the like, constructed and arranged whereby the removable portion of the connector may be lifted from its cooperative receptacle without the necessity of exerting any pull or strain on the electrical conductors associated 40 with the removable portion of the plug.

A further object of myinvention is to provide an attachment for disconnectable parts of electrical connectors, for example attachment plugs and the like, designed to providea quick break between the electrical contacts whereby arcing is substantially completely eliminated. a

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements, comprising my invention, may be varied in construction, proportions and arrangement, without 56 Figure 1 is a plan view of anattaclini'eHtplugiI gilblig 1 e arcingto a m'inirimm.

associated with a wall or baseboard receptacle and provided with one form of lifting device.

8. 2 is a front elevational view of the ar-" rangement shown in Figure 1. N Fig. 3 is an elevational view of an attachment plug equipped with my improved lifting devices- Fig. 4 is an elevational view of a radio tu equipped with a lifting device.

Fig. 5 is an elevational view of an electrical connector, showing a modified form of liftin g device. v Fig. 6 is a plan view of the arrang me'nt shown f in Fig. 5.

Fig. 7 is a. side eleyational view of another. modification of the lifting device; and f Fig. 8 is a front view of the arrangement shown in Fig. 7. v

Referring to the drawing and more particu larly to Figures 1 and 2, there is shown a wall or baseboard receptacle designated generally by numeral I, the opening to the interior of the receptacle being covered by means of a suitable plate 2. Seated in electrical connectionwith the contacts of the receptacle is an attachment plug member having a body portion 3 and contact members 4 adapted to frictionally engage with the contacts, not shown, of the receptacle. Attached to the body portion 3 of the plug is a lifting device comprising a. base member 5 having a pair of symmetrical arcuate shaped arms 6 pivotally mounted thereon at diametrically opposite points I. The arm members are formed with cam surfaces 8 and are interconnected by means of cross-piece designated generally by numeral 9, the cross-piece being bent to'form'a lip or flange portion l0, adapted to serve as a han ile or gripping member for the purpose of moving the arms of the plug lifter about their pivotal points.

The base 5 of the lifting device is designed to encircle the body portion 3 of the attachment plug cap and is detachably clamped thereon by means of setscrews H and adjustable nuts II. The lifting device may be made of metal or other suitable material of suflicient thickness to provide necessary rigidity so that the-arms will not become bent or distorted in the normal operation of the device. In order to remove an attachment plug cap from its seated position in normal to the plane of the receptacle contacts.

In other words, due to the design and configuretion of the, cam surfaces. andv by, spacing arms n ramfi ssteigsf Pea,

tube from'its socket or recep'tacl 'th mb rin befits-tied form distribution of the forces is obtained, with the result that the plug is forcibly pulled away from the receptacle in the same manner as if thepull were exerted on the cord, but without the danger of loosening the cord contacts or bending the blade members. It will be further, noted in connection with cam surfaces 8, that they are designed to provide a positive lifting of the cap substantially as soon as they contact the surface of the receptacle, insuring a quick breakge tsetsggor f. 7 rediicing Referring to, Fig. 3, there is shown an attachiment. plug comprising a cap member l3 and a threadedba' e I In this arrangement the lift in'gdevicefwhich is the same as that desscribed in connectiomwith arrangements'shown in Fig- .ures 1 and .2, is, attached to the body portion of cap I! by'means'hr screws IS, the cam stirfaces ;.8.;of-:'arms 6, being adapted to contact with periphery. of th hea d 1. h h arms'are turned awn'war "1 member.-

-Fig 4j there isshown av tube It equippedwith a mung device 5 of the lifter is clampedtdth a the tube and whenit is desired to esteemetions of the arcuatearms'contaet thesup porting base or plate for the tubes' forcibly}; lifting the tubes out ofthe ir sock'e fyf Referring to Fig. 5, there 'is'="shown "a mod ifi ed form of plug lifteradapted forfu'se in connection with a largertype attachment-plugs; connectorf" and more particularly plugsfof the' characterused for making connection with devices requiring a "35 comparatively high current. itrrangement, the arms are attachedftdvertical mem-q bers l1, iormedby bending thebase 5* upwardly at a right angle to the plane of the base. "The connector, which'is of conventional construction; 40 comprises an upper portion l8, IB'having contact blades or elements 20. [The hori- 'zontal portions 5 of the lifting device base 5' may be conveniently attached "to the plug' by inserting them between the separable of the plug and using the standard set screws or bolts 2|, associated with the plug partsfor the purpose of holding the lifting device-basein fixed Position; Referring to Figs. '7 and 8 there'is shown' 'a modified form of attachment-plug cap lifting de vice,- wherein the arms 'are formed with double arcuate or cam portions. In this arrangement, base member 5 of the lifting deviceisthe same as that described in connection'with'the device shown in Figures'l and 2,howeverfit' willjbe noted that the arm members-"6areprovidedwith arcuate portions 8' whicharesubstantiallyinf the shape of a semi-circle, 'so'thatfthe plugjcap f may be lifted from its receptacle byi'rotating the arms about their pivotal points ineitherdireq tion. By means of this arrangemen e plug] 1 can be inserted in a receptaclawith'ou regard" to the position or the arcuate portion ortheja a, 1 It will be further noted that-the" 1 6 are provided; with looped formed by expanding the materialb r arms and the cross piece respectivel pose of' the looped portions is'toiprovide port and. strain resistor for thepord ed with the plug cap. The cord veniently tied embodiment of my invention, I wish it to be understood that Ido not confine myself to the precise details of construction herein set forth, by way of illustrations as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing ,from the spirit of the invention, or exceeding the scope of the appended claims.

What I claim is:

1. An electrical connector including a body portion having contact members adapted to frictionally engage with contacts of a cooperative receptacle, means mounted externally of said body portion adapted to forcibly disconnect the contact members, comprising a base, means to readily detach said base from the body portion of the connector and a crank member having a receptacle, means mounted externally of said body portion adapted to forcibly disconnect the contact members, comprising a split ring adapted to encircle the body portion of the connector, means to clamp the ring in operative position on said body portion, and a crank member pivotally -mounted upon the ring, said crank member having an arm formed with a cam surface, said cam surface of the arm contacting with the associated receptacle when the portion of the arm remote from the cam surface is moved-about its pivotal point in the direction of the receptacle.

3. An electric connector, including a body portion having contact members adapted to frictionally engage with contacts of a cooperative receptacle, means mounted externally of said body portion to forcibly disconnect the contact members, comprising a split ring adapted to encircle the body portion of the connector, means to clamp the ring in operative position on said -body portion, and a crank member pivotally mounted upon the ring, said crank member having a pair of arms each formed with a cam surface, the cam surfaces contacting with the associated receptacle when the portions of the arms remote from the cam surfaces are moved about their pivotal'points in the direction of the receptacle.

4. An'electric connector, including a body portion having .contact members adapted to frictionally engage with contacts of a cooperative receptacle, means mounted externally of said body portion to forcibly disconnect the contact members, comprising a split ring adapted to encircle the body portion of the connector, means to clamp the ring in operative position on said body portion, and a crank member having a pair of symmetrical arcuate shaped arms providing cam surfaces pivotally attached to the base at diametrically opposite points, said cam surfaces contacting with the associated receptacle when the portions of the arms remote from the cam surfaces are moved about their pivotal points in the direction of the receptacle.

' JAMES J. SHEERAN. 

